var _isArray = require('./_isArray');
var _slice = require('./_slice');


/**
 * Similar to hasMethod, this checks whether a function has a [methodname]
 * function. If it isn't an array it will execute that function otherwise it will
 * default to the ramda implementation.
 *
 * @private
 * @param {Function} fn ramda implemtation
 * @param {String} methodname property to check for a custom implementation
 * @return {Object} Whatever the return value of the method is.
 */
module.exports = function _checkForMethod(methodname, fn) {
  return function() {
    var length = arguments.length;
    if (length === 0) {
      return fn();
    }
    var obj = arguments[length - 1];
    return (_isArray(obj) || typeof obj[methodname] !== 'function') ?
      fn.apply(this, arguments) :
      obj[methodname].apply(obj, _slice(arguments, 0, length - 1));
  };
};
